System for flowing wells



Feb. 28, 1939. X I J w. TAYLOR,

SYSTEM FOR FLQWING WELLS Filed Dec. 31, 1956 2(0 Z 25 32 a4 2.5 if u 5/Patented Feb. 28, 1939 UNITED STATES PATENT OFFICE 2 Claims.

through a pipe or tubingby means of a lifting fluid which is injectedinto the eduction or production pipe at stages or intervals along itslength so as to obtain a step by step of lifting action due to theaeration of the column of liquid in the production tubing or pipe.

It is of course desirable to control the operation of these valves so asto permit the injection of a minimum volume of lifting fluid so as toobtain the desired lifting effect and to have the A valve remain closedwhen no lifting fluid is needed at that particular elevation.

The present valves are designed to operate at predetermined pressuredifierentials; that is, to

operate, depending upon the difierence in pressure on the inside and theoutside of the production tubing, it being the practice to enclose theproduction tubing in the casing so as to form a reservoir for thepressure or lifting fluid and to incorporate the control or flow valvesin the string of tubing so that they will be subjected to the pressurein the reservoir and also to the pressure inside of the productiontubing.

It will be readily apparent that a well producing a heavy viscousoilwill require operation -of the valves at a greater pressure differentialthan would a well which produced a comparatively light oil in whichthere is a substantial amount of gas in solution. It is also, therefore,

40 apparent that a valve having the same size inlet cannot be used forboth of the foregoing conditions because in one instance an'insufficient amount of lifting fluid would be admitted and in the otheran excessive amount of lifting fluid would be admitted. It is thereforevery diillcult to design and arrange a series of valves for any one wellwhich will operate at .the proper pressure differential when they areinserted in a long flow line of production tubing. This is par-.ticularly true where the pressure on the inside of the tubing isreduced as it approaches the surface because much of the gas may comeout of solution or move in the well so that there is a greater ratio ofgas to oil nearer the surface than there is in the lower regions of thewell.

By actual experience it has been ascertained that where a ball valvemember is provided in a flow valve of the type herein disclosed even ifthe differential pressure at which the valve is to close is not correctthat the ball valve will 5 not as a matter of fact move to its upperseat and shut off the flow of fluid but will be buoyed upwardly by theincoming flow of gas in such a manner that a chattering action is set upby the ball valve member engaging its lower seat and 10 then beingquickly moved 011 its seat by the incoming gas. This chattering actionresults in a constant hammering effect upon the valve seat, and thepresent invention concerns itself with providing a particular type ofseat in which the 15 tial pressure at that particular location, so thatthe chattering action will cease and the valve will operate in itsintended manner.

One of the objects of the present invention is therefore to provide aseat for a ball valve which 30 has a tapered portion such that as theseat wears away the orifice being closed by the valve will graduallyincrease in size, depending upon the differential pressure which isproper to maintain the valve in a deflnite open or closed position 35depending upon the pressure difierential which is present at the valvelocation.

Another object of the invention is to arrange a series of valves upon astring of production tubing at different elevations thereof so that thevalves will automatically seat themselves by hammering their seats untilthe seat takes a configuration such that it will admit the proper amountof fluid therethrough to maintain a differential such that the valvewill be balanced 45 and will move to either direct open or closedposition.

Another object of the invention is to pro ide a system for controllingthe flow -of fluid from wells by automatically providing a pressure dif-50 'ferential at each stage of the elevation of the liquid from the wellwhich will most efficiently elevate the fluid at that elevation.

Another object of the invention is to provide a series of unloadingvalve-son a string of propipe of tubing l5.

the column of liquid above each particular valv in a successiveoperation. I

Another object of the invention is to provide 1 an unloading valve whichwill open when a predetermined difierential pressure occurs therein soas to unload the column of liquid above that valve and to thereafterremain closed until another load oiliquid occurs above that valve tocreate the predetermined pressure that will cause opening of the valve.

Another object of the invention is to provide a method of automaticallyseating an unloading valve by causing a hammering action of the valve ona seat which will vary in size as aresult of the hammering until anorifice is in this mmner created which will provide a flow to efiect thedesired predetermined pressure dlflerentlal at that particular locationoi a valve.

Other andfurther objects oi the invention will I be readily apparentwhen the following description is considered in connection with theaccompanying drawing, wherein:

Fig. l is a side elevation. oi a well which is equipped with the presentsystem of flowing the well and illustrates the arrangement or the valveson the production tubing.

Fig. 2 is a vertical section or a piece oi tubing showing one of thevalves attached to the exterior of the tubing.

Fig. 3 shows another form of the production tubing wherein thevalve hasbeen attached to the interior of the Figs. 4, 5 and d are verticalsectional views of the ball and seat construction which hasautomatically adjusted itself to provide difierent size orifices foradmitting the pressure fluid.

In Fig. l the well casing is illustrated generally at 2 and extends intothe well bore, being closed by the casing head 3. This casing alsoserves to support a string of tubing l which extends into the well inthe form of an eduction controlled by a valve b above the casing head'3.

The area i between the casing 2 and the tubing 5 is in the form of areservoir for pressure fluid which may be delivered to the well throughthe inlet pipe either 3 or Attached on the tubing 5 are a seriesoiunloading valves indicated generally at til, it and 112, whereas theluck-d or flow valve is shown generally at 53. All of these valves arecarried by the tubing as is the strainer it attached to the lower endthereof. If desired, a suitable packer or other restriction may beprovided around the tubing 5 in order to form a seal with the casing 2to limit the size of the reservoir i. 0n the other hand, in some wellsno such packer is provided and none is illustrated in the presentinstance.

Fig. l is merely diagrammatic and it is intended that any number ofunloading valves can be provided at spaced intervals along thetubiug,depending upon the circumstances encountered, which, of course, varywith the depth of the well,

' the viscosity of the oil, the size of the tubing,

The flow from this tubing is r duction tubing which will operate tounload The valve itself is contained within a housing '23 which includesa valve chamber 2t with the passages 25 and 26 leading therefrom intotheinside of the flow pipe.

The lower end of the chamber 2d is threaded at 2B in order to receivethe nipple 30; such nipple is threaded in position and serves as a seatfor the valve member which is here shown in the form of a ball. The topof the chamber it is also provided with a valve seat 32 which receivesthe ball member when the pressure difierential is such that the valvemember will move to its upper seat to out ed the inflow of pressurefluid. In the positions shown in Fig. 2 the pressure is greater insideor the tubing and there is no inflow of pressure fluid.

Fig. 3 shows the housing 23 as having been positioned inside of the sub2d instead of on the outside as shown in Fig. 2. Otherwise theconstruction is substantially the same except that the seat portion 3 5for the valve member 3i is formed in the housing 23. It is to beunderstood, however, that it may be formed in a separate nipple in thesame manner as it is formed in Fig. 2, so long as the pressure fluid canenter the nipple in order to be controlled by the valve member. Theother parts in Fig. 3 are the same as in Fig. 2.

Particular attention is directed to the peculiar construction of thenipple of the valve seat memher 353, and it will be observed that theinlet, passage lh is of uniform diameter, for a substantial length, andit is then reduced in diameter by the tapered section ii. Beyond thetapered section M is a second cylindrical section or of reduced size andthen the upper portion of the nipple is cupped at 63 to form theoriginal valve seat, reference being had to Fig. 4. The valve member illis shown as seated in Fig. 4 in the cupped por-.

tion in the manner which it will seat when the parts are new and readyfor installation in the well.

With the, parts assembled as shown in Fig. 4 the valves will be attachedto the tubing and lowered into the well bore and the pressure will beapplied thereto. If there is a load of oil in the tubing 5 above thevalve ill and ii the head of the liquid in the chamber l is above thevalve it then of course the pressure which is introduced into thereservoir i will cause depression of this column of liquid until itmoves down to the level of the valve ill. 'When this occurs the pressurein the reservoir i will undoubtedly be greater than the back pressureexerted through the passages 25 and 2b in the chamber 2d and upon thevalve member 3i due to the load of liquid in the tubing 5, so that adifierential pressure will be exerted on the valve member 3i inthe valveIll and it will move upwardly to permit an inflow of pressure fluid.This pressure fluid aerates the column of liquid in the tubing 5 abovethe valve ill and assists in discharging it from the well. The removalof this load of oil in turn reducesthe pressure applied on the column ofliquid which remains in the tubing 5 below the valve in and above thevalve I l, and as the pressure on the inside and outside of the tubingwill naturally tend to equalize itself the head of the liquid in thereservoir will again move downwardly until it reaches the next unloadingvalve ll.

The pressure fluid will then enter thevalve ll, aerate the column ofliquid above that valve, and discharge that bodyof liquid from the bodyoi the well. This operation will of course be reing above any particularunloading valve has satisfactory.

been discharged that the differential pressure which predominates on theoutside of the valve will keep the valve member 3| against the upperseat 32 in closed position to prevent entrance of pressure fluid. Thisis the theory of operation which is presumed to hold true in actualpractice and a majority of the wells are equipped with valveconstructions in accordance with this theory.

The present invention, however, substantiates the discovery by thisapplicant of the fact that the ball valves 3| do not moveupwardlyagainst the seat 32 and remain 'in this closed position due todiiferential pressure. Various circumstances cause a phenomenon ofoperation ofball member 3| and it has been found that this ball membermerely floats on top 'of the incoming pressure fluid and is buoyed up inthe chamber 24 so that there is a flow of fluid around the ball memberand through the valve continuously; that in actual operation this ballmember 3| merely bounces up and down on its seat 48- at a very rapidrate and that as a matter of fact a very substantial hammering actionoccurs on the valve seat 43 and in the past where the entire passage 40was of uniform diameter it has been found that the ball member .wouldhammer its' way completely through the passage pounding a seat as itwent so that in a 'very short period of time the seat was destroyed anda new nipple 30 had 'to be provided. The nipple 30 may be made of anydesired material, brass having been found As the result of such actionan extensive study was made of the conditions encountered in a well andthe taper 4| -was provided in the seat 32 so that as the actual seatingsurface 43 was moved downwardly through the hammering action the size ofthe orifice 42 would vary and then become enlarged as the seat portionwas moved downwardly along the taper 4|, and that as a matter of factwhen the seat 43 reached a certain position along the taper 4|thereafter-the hammering action would discontinue and that the pointwhere the hammering action ceased varied in different valves which werepositioned along the tubing 5. Further, that there was a substantiallyuniform difference between the size of the orifice 42 between adiacentvalves and that the change in the size of the orifice was uniform alongthe tubing, where the spacing of the valves was uniform.

It was therefore determined that there was a predetermined and definitedifferential pressure at which each valve"would operate properly, andthat in order to maintain this proper differential pressure it wasnecessary to adjust the size of -fice varied with the position of thevalve in the well because of the diilerence in the conditionsencountered by each valve and the difference in I the head of liquid onthe inside or the outside of the production tubing.

With the foregoing in mind, therefore, the taper 4| has been provided onthe passage 40 so that while all of the valves when positioned in thewell are of uniform construction they, in a very short time due to theautomatic seating conditions which are encountered in the well, willseat by an automatic operation which will depend upon its location inthe well.

As an instance of this, in Fig. 4 the valve might maintain its seat 43as-illustrated with the orifice 42 of small diameter, whereas the nextvalve on the string of tubing would be represented by Fig. 5 where theball member II has womaway the original seat and the uniform portion ofthe inlet orifice and has arrived at a position such that part of thetaper 4| has been worn away and the seat 43 has moved to the positionshown. Naturally the orifice 42 is somewhat larger in Fig. 5 than it isin Fig. 4 and a greater amount of pressure fluid will naturally beadmitted through this larger orifice. I

Fig. 6 shows another valve positioned at a different location on thetubing wherein the entrance orifice 42 has been substantially enlargedand the taper 4| has almost been worn away.

The applicant has therefore worked out a system by which valves ofuniform size and capacity are applied to a well tubing but they are ofsuch construction that each valve will automatically workout its ownproblem at that particular elevation so that within a very short timethe seat for the valve has so adiusted itself due to the differentialpressure encountered that it will admit the proper amount of pressurefluid in order to unload the column of liquid in the well above thatvalve and will then move to closed position without further chatteringand until such proper size entrance orifices have been created that thevalve performs a chattering operation which has been outlined inconnection with the present invention, to create a seat of the propersize so as to eliminate the chattering action. The pressure gauge 50 isshown in Fig. 1 and its connectionbl with the tubing 5 carries a valve52 while the connection 53 to the flow line 9 and casing 2 carries avalve 54. By manipulating these valves the pressure of either the casingor tubing may be determined or the pressure can be equalized by openingboth valves.

In actual practice a set of seven valves were applied (all of uniformconstruction), to a well and the well placed in operation. Within aperiod of forty-eight hours an inspection was made of the valves and itwas found that each valve had automatically seated itself by creating aseat of the proper size such that the desired flow of pressure fluid waspermitted and further inspection of these seven valve seats showed thatthe size of the'openlng became larger in each succeeding valve as thedepth of the well increased, the bottom valving creating the largerentrance opening so that the pressure differential between the insideand outside of the tubing was shown to be smaller as the operationprogressed down the well. In other words, the upper valve wore but verylittle and each succeeding valve down the tubing received more wearbefore it anived at a balanced position.

Further inspection of a system of valves of this vation in the well. Theforegoing is merely given as an illustration of the actual operation ofthe system '1. In a flowing valve for wells 9. housing, a

valve chamber therein, inlet and outlet passages for said chamber, avalve member in said chamber, seats at opposite ends of said chamber atsaid inlet and said outlet, one of said seats being of a material to bedeformed bysaid valve member to change the size of the entry of thehousing.

2. A system of equipment for a well, including a series of flowingvalves, a tubing in the well, flow valves spaced along the tubing, eachof said flow valves having an inlet orifice and an oppositely taperedvalve seat, a ball valve on said seat,

said seat being of a material which will be deformed by the chatteringof said ball valve so that the valve will chatter on its seat to deformthe seat and thus change the size of the inlet orifice as said seat isdeformed along the taper until the pressure fluid being admitted createsthe differential pressure at that elevation which causes the valve tooperate without chattering.

JAMES- W. TAYLOR.

